This study was done to compare three method for diagnosing early pregnancy as transrectal ultrasonography, serum progesterone assay, cytological examination of vaginal smear on days 21th, 36th and 46th post-inseminated and of the embriyonic losses in the cows. Fourty four Holstein cows, between 3-6 years old were used as materials. The sensitivity and specifity of the ultrasound examination in the 21th were 62.3% and 59.2%, respectively, but were 100%-100% and 100%-100% in the 38th and 46th days, respectively(P< 0,05). Progesterone concentration in the non pregnant and pregnant cows showed significant differences on the 21 th day {P< 0.001). Total Intermediate and parabasal cell count in the non pregnant and pregnant cows determined significant diffences on the 21 th, 38th and 46th days. In conclusion, Ihe use of transrectal ultrasonography of cows on days 38th and 46th of gestation offers a rapid, accurate and reliable diagnosis of pregnancy. In cows, diagnosis pregnancy using serum progesterone was detected as reliable method on 21^ days. Pregnancy diagnosis by examination of the celluler content of vaginal smear was not reliable because of minimum and maximum intermediate and parabasal cell count were similar in the non pregnant and pregnant cows.